The Crew Exploration Vehicle (“CEV”) and the Lunar Surface Access Module (“LSAM”), to be used for space exploration, will require new life support systems to support the crew on journeys lasting from a few days to several weeks, or longer. These life support systems should also be designed to reduce the mass required to keep humans alive in space. Water accounts for about 80 percent of the daily mass intake required to keep a person alive. As a result, recycling water offers a high return on investment for space life support. Water recycling can also increase mission safety by providing an emergency supply of drinking water, where another supply is exhausted or contaminated. For a three-day CEV mission to the International Space Station (ISS), water recycling can reduce the mass required to be transported to provide drinking water by 65 percent, when compared to stored water. For an 18-day Lunar mission, a mass savings of about 70 percent is possible. These technologies also increase safety by providing a lightweight back-up to stored supplies, and they allow astronauts to meet daily drinking water requirements by recycling the water contained in their own urine. During a three-day CEV emergency return to Earth, this capability could be critical to the crews' survival. These technologies also convert urine into a concentrated brine that is biologically stable and non-threatening and can be safely stored onboard. This approach eliminates the need to have a dedicated vent to dump urine overboard. This would result in one less through hull fitting on the CEV spacecraft (a significant safety advantage).
What is needed is a system for recycling urine (1) to provide a renewable source of drinking water, (2) to reduce the mass of water initially stored aboard a spacecraft, (3) to provide a temporary source of additional nutrients for use by a spacecraft occupant, (4) to reduce the volume of, and provide a biologically safe form of, urine residuals (i.e. waste or non-water residues from urine) temporarily stored aboard a spacecraft and (5) reduce or eliminate the need for urine dumping during a space voyage.